1. Field of the Invention
The present invention relates to an air conditioning method and apparatus for electro-chemically controlling the humidity and the oxygen-concentration within a case by the use of an ion exchanger polymer electrolyte.
2. Description of Related Art
The condensing method, in which a temperature is lowered to condense steam in an atmosphere, and the absorbing method, in which steam is absorbed by a desiccating agent such as silica gel, have been known for the conventional dehumidifying method. The condensing method has exhibited a problem in that it is not suitable for the use where it is not appropriate to lower a temperature while the absorbing method has exhibited a problem in that the regeneration treatment is required.
A method using an ion exchanger polymer electrolyte comprising a cation exchanger polymer electrolyte (Japanese Patent Application Laid-Open No. Sho 61-216714) has been known as an air conditioning method, in particular a dehumidifying method, solving such problems.
FIG. 1 shows a working condition of the conventional dehumidifying method disclosed in Japanese Patent Application Laid-Open No. Sho 61-216714. Referring now to FIG. 1, reference numeral 6 designates a case for an object to be dehumidified. The case 6 is provided with a cell 10 having an anode 2, a cathode 3 and a cation exchanger polymer electrolyte 1 sandwiched between both the electrodes 2, 3 so that the cell 10 may pass through a wall of the case 6. A surface of the anode 2 is in contact with an ambient atmosphere 7 inside the case 6 while a surface of the cathode 3 is in contact with an atmospheric air 8. The anode 2 and the cathode 3 are connected to a DC power source 4 through lead wires 5 and DC voltage is applied between both the electrodes 2, 3 as far as hydrogen is not generated from the cathode 3.
Next, the operation is described. Steam in the ambient atmosphere 7 acts upon the anode 2 in such a manner as expressed by the following equation (1): EQU 2H.sub.2 O.fwdarw.O.sub.2 +4H.sup.+ +4e.sup.- ( 1)
Oxygen formed by this reaction is left in the case 6. On the other hand, hydrogen ions formed are transferred onto the cathode 3 through the cation exchanger polymer electrolyte 1 where hydrogen ions act upon oxygen in the atmospheric air 8 in such a manner as expressed by the following equation (2): EQU O.sub.2 +4H.sup.+ +4e.sup.- .fwdarw.2HO (2)
As a result, water (steam) is decomposed on the side of the anode 2, that is, the side of the ambient atmosphere 7, while water is formed on the side of the cathode 3, that is, the side of the atmospheric air 8. And, as a whole, water is transferred from the ambient atmosphere 7 inside the case 6 to the atmospheric air 8 and thus an inside of the case 6 is dehumidified.
The above described air conditioning method (dehumidifying method) using the cation exchanger polymer electrolyte has exhibited the following problems:
Steam is reduced (the humidity is reduced) and the oxygen-concentration is increased on the side of the anode 2, in short, in the ambient atmosphere 7 inside the case 6 while steam is increased (the humidity is increased) and the oxygen-concentration is reduced on the side of the cathode 3, in short, on the side of the atmospheric air 8. Where it is desired to reduce both the humidity and the oxygen-concentration in order to suppress the progress of corrosion, a problem has occurred in that the above described air conditioning method using the cation exchanger polymer electrolyte can not be applied.